How to run a single test from a Rails test suite?

Question

How can I run a single test from a Rails test suite?

rake test ANYTHING seems to not help.

possible duplicate of [running single rails unit/functional test](http://stackoverflow.com/questions/274349/running-single-rails-unit-functional-test) — Ciro Santilli OurBigBook.com, Jun 25 '14 at 14:31

score 195 · Accepted Answer · edited Jul 10 '22 at 18:45

195

NOTE: This doesn't run the test via rake. So any code you have in Rakefile will NOT get executed.

To run a single test, use the following command from your rails project's main directory:

ruby -I test test/unit/my_model_test.rb -n test_name

This runs a single test named "name", defined in the MyModelTest class in the specified file. The test_name is formed by taking the test name, prepending it with the word "test", then separating the words with underscores. For example:

class MyModelTest < ActiveSupport::TestCase
  test 'valid with good attributes' do
    # do whatever you do
  end

  test 'invalid with bad attributes' do
    # do whatever you do
  end
end

You can run both tests via:

ruby -I test test/unit/my_model_test.rb

and just the second test via

ruby -I test test/unit/my_model_test.rb -n test_invalid_with_bad_attributes

edited Jul 10 '22 at 18:45

BinaryButterfly

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answered Oct 01 '09 at 23:44

Darryl

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This doesn't work for me (on functional or unit tests). I get `0 tests, 0 assertions, 0 failures, 0 errors`. Rails 3.0.7. – B Seven Dec 10 '11 at 15:32
12

I'm personally a fan of the regex form: `-n "/good/"`. Shell escaping is always fun, so I tend to stick to simple regexes, but it's far easier than writing out the full test name all the time. – Groxx Feb 20 '12 at 20:15
5

It's important to note that for this to work, you should not be in the MAIN directory as specified in the response but in the subdirectory which contain the `test/` folder. For example, if I want to run the test `activesupport/test/core_ext/array_ext_test.rb` I should be in `activesupport/` first. – Vincent B. May 11 '12 at 07:13
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@Groxx - Finally a solution! Thank you! `-n "/good/"` worked. – B Seven Aug 17 '12 at 16:32
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Be careful running this in 2018+. It bypasses some testing tasks built into rails (like db:test:prepare) which are used for many things, like swapping local data for fixture data, and restoring it again. Running this blew away my local database. Consider a solution that uses the built-in rails testing tasks, like https://stackoverflow.com/a/47006811/1154642 (which worked for me). – bryanbraun Sep 15 '18 at 19:57

laffuste · Answer 2 · 2016-05-11T05:24:29.947

134

Run a test file:

rake test TEST=tests/functional/accounts_test.rb

Run a single test in a test file:

rake test TEST=tests/functional/accounts_test.rb TESTOPTS="-n /paid accounts/"

(From @Puhlze 's comment.)

edited May 11 '16 at 05:24

answered Apr 13 '14 at 17:13

laffuste

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Also, if you want to run a single test in in the given file you can add a TESTOPTS environment var which will be passed to the test. E.G. rake test TEST=tests/functional/accounts_test.rb TESTOPTS="-n /paid accounts/" – Puhlze May 08 '15 at 15:21
2

if the latter test command doesnt work, try `rake test TEST=tests/functional/accounts_test.rb TESTOPTS="-n '/paid accounts/'"` (enclosing `/paid accounts/` with single quotes) – rrw Aug 22 '16 at 09:23
Documentation: http://www.rubydoc.info/gems/rake/13.0.1/Rake/TestTask https://github.com/ruby/rake/blob/master/doc/command_line_usage.rdoc – itsnikolay Feb 16 '20 at 17:03

score 52 · Answer 3 · answered Jun 28 '16 at 14:38

52

For rails 5:

rails test test/models/my_model.rb

answered Jun 28 '16 at 14:38

James

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But this runs all test cases in the file, the question asks to run a single test... – user000001 Sep 07 '17 at 13:50
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You can run a single test by appending a line number to a filename:`bin/rails test test/models/user_test.rb:27` – Segfault Mar 25 '20 at 18:16

score 51 · Answer 4 · answered Oct 30 '17 at 00:53

Thanks to @James, the answer seems to be:

rails test test/models/my_model.rb:22

Assuming 22 is the line number of the given test. According to rails help:

 $ rails test --help
You can run a single test by appending a line number to a filename:
    bin/rails test test/models/user_test.rb:27

Also, please note that your test should inherit from ActionDispatch::IntegrationTest for this to work (That was my mistake):

class NexApiTest < ActionDispatch::IntegrationTest
.
.
.

This seems to be the best answer based on the Rails guides, at least for testing a specific line. — tfantina, Oct 30 '17 at 10:51

score 20 · Answer 5 · edited Dec 22 '21 at 12:17

20

Rails 5

I used this way to run single test file (all the tests in one file)

rails test -n /TopicsControllerTest/ -v

Another option is to use the line number (which is printed below a failing test):

rails test test/model/my_model.rb:15

edited Dec 22 '21 at 12:17

Christopher Oezbek

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answered Dec 16 '16 at 11:55

Alupotha

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this is the best answer to the question for recent rails versions, +1 – user000001 Sep 07 '17 at 13:52
Note the word inside a pair of forward slashes can match any of the method names. Just be careful any space has to be replaced with `_`. For example, `-n "/many_num/"` would match `test "many numbers" do` and `test "many numbered items" do` etc. – Masa Sakano Jun 28 '21 at 15:46
in Rails 6, you have to use `rake test TEST=test/models/MyClassTest.rb` – Siwei Oct 10 '22 at 04:14

score 10 · Answer 6 · edited Oct 14 '21 at 16:24

10

In my situation for rake only works TESTOPTS="-n='/your_test_name/'":

bundle exec rake test TEST=test/system/example_test.rb TESTOPTS="-n='/your_test_name/'"

edited Oct 14 '21 at 16:24

Joshua Pinter

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answered Feb 05 '19 at 22:16

N0xFF

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I noticed this, too. I could have sworn it worked without the `=` (the one in `-n=`) in the past, but now it keeps thinking it's a filename instead. – Steve Apr 07 '21 at 23:42
Thank you so much for this answer, now I can finally run specific tests... – Guido Tarsia Oct 21 '21 at 21:01

score 5 · Answer 7 · answered Dec 20 '11 at 20:15

5

To run a single test in the actual Rails suite:

bundle exec ruby -I"railties/test" actionpack/test/template/form_options_helper_test.rb

answered Dec 20 '11 at 20:15

Brian Rose

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score 4 · Answer 8 · answered Oct 03 '09 at 15:19

That was a silly midnight question of mine. Rails kindly prints the command it is executing upon rake test. The rest is a cut and paste exercise.

~/projects/rails/actionpack (my2.3.4)$ ruby -I"lib:test" "/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake/rake_test_loader.rb" "test/controller/base_test.rb"

score 4 · Answer 9 · answered Nov 27 '16 at 21:26

4

The best way is to look directly into the guides: http://guides.rubyonrails.org/contributing_to_ruby_on_rails.html#running-tests

cd actionmailer
bundle exec ruby -w -Itest test/mail_layout_test.rb -n test_explicit_class_layout

answered Nov 27 '16 at 21:26

Diego Plentz

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score 3 · Answer 10 · answered Sep 13 '21 at 16:01

To re-run a test that just failed, copy-n-paste the failed test name into

rails test -n [test-name]

EXAMPLE

When your test suite reports this:

> rails test
   ...
   Error:
   PlayersControllerTest#test_should_show_player:
   ActionView::Template::Error: no implicit conversion from nil to integer

you rerun the failing test with this:

rails test -n PlayersControllerTest#test_should_show_player

Aupajo · Answer 11 · 2009-10-01T22:27:23.767

2

If you want to run a single test, you can just run them as a regular Ruby script

ruby actionmailer/test/mail_layout_test.rb

You can also run a whole suite (eg. ActiveRecord or ActionMailer) by cd-ing into the directory and running rake test inside there.

edited Oct 01 '09 at 22:27

answered Oct 01 '09 at 22:20

Aupajo

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Not in Rails -- at least not with the default test files generated. They have "require 'test_helper'" on the first line, but the load path won't have been set up in time. If you change every first line to an explicit require ("require File.join(File.dirname(__FILE__), '..', 'test_helper')"), then your solution works. – James A. Rosen Oct 01 '09 at 22:30
ahem, that's `require File.join(File.dirname(__FILE__), '..', 'test_helper')` – James A. Rosen Oct 01 '09 at 22:31
@Gaius Double-checked. First one doesn't work, but `cd`-ing in does. Just to be clear (I'm not sure if I'm mis-reading this, but you did say "generated test files"), this is for the Rails library itself, *not* a Rails project. – Aupajo Oct 10 '09 at 03:14

score 2 · Answer 12 · answered Mar 01 '22 at 23:03

2

If rake is running MiniTest, the option is --name instead of -n.

rake test TEST=test/unit/progress_test.rb TESTOPTS="--name=testCreate"

answered Mar 01 '22 at 23:03

Don Kirkby

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Nice one. This was giving me a bit of a headache. – vinibol12 Jun 19 '22 at 18:09
Funny, I hit that with `Test::Unit`. See https://github.com/ruby/rake/issues/490 So you say that it is not about `TestTask` but about the underlying test framework? I believe it is an issue with the `TestTask` though because if I run directly with Ruby, then it works: `bundle exec ruby test/gnuplot_printer_test.rb -n /write/`. idk if that's the same with minitest though. – akostadinov Apr 06 '23 at 13:03

score 0 · Answer 13 · answered Oct 21 '16 at 19:05

0

First, access the folder of the lib you want to test(this is important) and then run:

~/Projects/rails/actionview (master)$ ruby -I test test/template/number_helper_test.rb

answered Oct 21 '16 at 19:05

Diego Plentz

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score 0 · Answer 14 · answered Dec 11 '19 at 21:04

0

Rails folder

  bundle install
  bundle exec ruby -I"activerecord/test" activerecord/test/cases/relation/where_test.rb

Note you need to load appropriate folder: "activerecord/test" (where you have test)

answered Dec 11 '19 at 21:04

Igor Kasyanchuk

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How to run a single test from a Rails test suite?

14 Answers14

Rails 5

EXAMPLE

Linked